Safeguard your property with this reliable alarm. Its front-loading battery door means you can change batteries without removing alarm from mounting bracket. Door won't close unless battery is properly installed. Equipped with a tamper-resistant locking feature to alleviate concerns about theft & tampering. Includes feature that allows you to silences nuisance alarms. Adjustable mounting bracket for fast installation & perfect alignment. Requires 9V battery (incl.). Test / reset button tests all functions including battery. Power Source(s): 9V Battery; Mounting: Wall.